Aircraft of the rotary wing type



Feb. V14, 1950 Y R. E. MULLIN 2,497,465

AIRRAFT 01 THE ROTARY WING TYPE Filed July 27, i946 4 Sheets-Sheet 1 mmv rox. P055121 E, MULL/N 44TT0ENEYJ Feb. 14, 1950 R. E. MULLIN AIRCRAFT OF THE ROTARY WING TYPE Filed July 27, 1946 4 Sheets-Sheet 2 a s o ro o s I K INVENTOR. ROBERT E. MULL/N Feb. 14, 1950- R. E. MULLlN AIRCRAFT of THE ROTARY, .WING'TYPE:

Q 4 Sheeis-Sheet Z5 Filed July 27, 1.946

INVENTOR ROBERT E. MULL IN 2 BY "iiiiiiiwibu afiw/ ATTOENEYJ Feb. 14, 1950 v R. E. MULLlN AIRCRAFT OF THE ROTARY WING TYPE 4 Sheets-Sheet 4 Filed July 274.. 1946 v INVENTOR. 4 Pass/QT EJVULUN mgw ATTOENEYS andiposses Patented Feb. 14, 1950 *iUN ITI'HD .gQFFEliCE 2,497,465 mace-AFT OF THE Roman a/menus mRcbert EriMullin, Bremerton, Wash. Application Jilly 27, 1946; SHEPNOCGSQ625 3 4 Claims. (Cl..170-+.-180;2 5)

"I'lils' inventiomrelates toaircraft, and=-it" has I reference more particularly-to improvements in *aircraftof' the rotary wing types generally re- "ferred' to as helicopters;theprincipal object of "the invention being to provide novel improve- -ments, particula'rlyin wing relationship and parts :incorporated in the wings,"that providesb'etter hovering and vertical flight "ability; that produce greater lifting effect; thatflprovide for "better directional :control; "whereby propulsion 'or driv- Ting force for horizontal directional "iiight'is "'efieote'd" and'may' be variedithrough the rotating wings, and whereby better maneuverability and gzgreaterr speed'in suchrraft'is -made possible.

. it a objectof this'invention .to provide ran improved aircr aft of the :character f'statd sing the advantages :above stated, that is'characte'rized' by'a novel use'of dual air screws, for rotating wingsg and withwhi'ch air. screws novel devices .are used for controlling the speed ofl'flight'an'd .direction oftravel as well as'to efiect turning and stopping.

Gtherobjects of'thelinventlon reside in the details of construction, and combinationoi parts,

-ferred forms .ofwhi'ch. are illustrated in the achereinan. view .of .-.an..aircrait of thepresent'in- :companyingf drawings,v .w .Fig. 1 is .a top, .or.p1

eembodying the improvements oventiontherein. Figszl is aside view or the. same.

ir relationship and mode of operation,.

Eigfi? is...a longitudinal, sectional detailv of the top portion of 'theffus'elage, showing one or the air screws and its mounting and rotating means. Fig. .4 is a plan, or top view of the engine and itsdrive'shaftas extended tothe driving gears of the two air screws.

I Fig. '5'is a central, vertical sectionoi one of Tithe air screw mountingspindles, showingthe jaileroncontrol linkage as containeditherein.

TEigJ 6" is a horizontal section, on 'line' "6-4; J'cf 'Eig; 7 'shows a fragmental plan-view of apart of one of the wings of an air screw and aileron control. mechanism .associated therewith.

.'.Fig. .-8' is across section taken on line'-'8 .8 gin lFig; 7, showing .aileron movement.

-Fig; .9lis... a detail partly. in. elevation and partly :inI section .-of vthe propulsion. fin control devices ,eassociated withrani air screw.

. Fig. 10-=is a crcssrsectionxof a wing showing the 'rldispo's'ition =of a propulsion -fin' therein.

Refer-ring more in detail to-the drawings- 'In'one -of .its :present preferred forms of con- -struction, the-aircraft of thisinvention-comprises "a cabor fuselage, designated-in =its"entirety by reference character 10, equipped in suitable mannerwith landing, -wheels,- designated by numeral -11, preferably having caster "type mountings. The-fuselage, or-cab I0 is of'an elongated form, marrow in -'width and streamlined. Atthe top hand-adjacent its ends; thefuse'lage is formedwi-th suitable bearing housings I2 and I!" open at the -"top and-within which tubular, vertically directed spindles I3 and i3"-'are"iixed,-as seen 'in F-igbB, for the support and rotation thereon of the air "screws which, in Figs. 1. and 2,I have designated -in their entireties by referencenumerals IE-and '15.

It will be understood, by reference to" -Fig5'3,

"that" each "air'screw is formed with a central,

hollow hub portion l6, fromwhich' three radially -"'directed-and equally angularly spaced wings I! "extend. The two air screws are of the same 25 size and they rotate'in the same horizontal plane,

but in opposite directions, as. presently understood.

TTherel'ative position'of' the two air screws as "shownin-Figs. .1 and 2, 'is such that they overlap "in"'their"'operation. However, the inclination of *the'wings of eachis at such an upward degree in their outward extent from the screw axis that .in the turning of the screws, the wings ofione willpass. above those of the other; this being 'made, possible by reason of the fact that one screw .is inadvance'of the other and the screws. turn inloppos'ite directions, and thus. the .radialwings-of .each maintain. asort ofintermeshing relationshipbetween the wingsof the other.

Mounted for rotation about each of the spindles '-.l3,is .arelatively largeTbeveled gear wheel- 2.0, and each..of.these"has .a rather. elongated, .up-

nwardlyeexteriding hub portion 2| that is flanged about itsupper end and is bolted through this flange .to theflat .bottom face. of the hub- I6 .of the air screw .fordrivingthelatter. Each gear 20 .is supported upon an. upwardly facing. shoulder J31: of-the mountingqspindle, and, in turn, sup- .-ports the air screwfor its intended operation.

it is shown "in Fig. 3 that the upper end por- .tions of spindles I3 and .I3'-i are tapered as at l3x; to a partof reduced diameter and that these ,portionsextend into the. .hollow hub portions-.1; or thelair screwswand-that the :screws are-secured in the wing structure. I v suitable manner to the shaft and is controlled by the shaft movement.

- fixed at its ends to the spindle.

on the spindles by collars 22 that are applied over the tapered portions of the spindles against the base walls of the hubs, and held by nuts 23 that are threaded onto the reduced end portions of the spindles against the collars.

The air screws I and [5' are driven in synchronism and in opposite directions by a drive shaft 25 common to both, that is mounted lengthwise of the fuselage, in supporting bearings 26. At its ends, the shaft has bevel gear pinions 21 and 21' fixed thereon and operating in driving mesh with the bevel gears 20 which are air screws.

' 59. fixed to the The shaft 25, as observed in Figs. 3 and 4, is

operatively connected through a reduction gear mechanism, indicated at 28, with an engine 29.-' The engine may be of any suitable type for the work to be done, and its controls and accessories are not herein shown as they form no part of the.

invention; it being understood that they may be of any kind suitable for the work to be done.

Since each air screw is like the other, one only will be described in detail, with the understandingthat the description relates equally to both.

The radial wing portions of each air screw are designated by reference numeral l1. Each may be of conventional construction and of a length required for its particular use. In the present instance, each screw has three Wings, and each wing is fixed solidly to the central hub,

portion 16 at 120 intervals. Also, each wing is equipped at its outer end and at its trailing edge with an aileron 35, and this is functionally supported by a hinge shaft 36, as seen best in Figs. 7 and 8, for adjustment between the position in which it is shown in full line and in dotted lines in Fig. 8. The hinge shaft 36 extends in the longitudinal direction of the wing, and is revoluble in supporting bearings 40 fixed The aileron is fixed in.

For holding the ailerons in set positions and .for effecting an adjustment in their positions, vI have provided the hinge shaft 36 of each withv a belt wheel 42, fixed to the shaft, and about which a cable 45 is wound. Opposite end portions of the cable extend from the belt wheel,

The levers 44 of the several Wings are located j relatively close to the hub portion Of the screw f and the cables 45, as secured to the opposite ends of the levers, are drawn tight so that any movement of a lever will be translated to the ;corresponding aileron to swing the aileron t0 different positions of its adjustment.

As understood by the showing in Fig. 7, the

' levers 44, as mounted in the threewings of each air screw, are normally transverse to the longitudinal lines of the wings. It is desirable that,

in this aircraft, all aileronsof each screw should be operated together and to the same extent.

Therefore, I have provided mechanism as shown in Figs. 5, 6 and 7 for this mode of operation.

'- The mechanism as shown comprises a guide bearing block 58 that is fixed rigidly within the tubular spindle portion about which the screw" rotates by means of a cross plate 5| that is Vertically slidable through the bearing, and coaxial of the spindle, is a shaft or rod 56, which extends below, T and also -to adistance substantially above the"- A bearing, and into the hub portion I6 of the air screw. Rotatably fixed on the upper end of the shaft 56 is a collar 58 and slidable 0n the shaft, at a distance below the collar 58, is a sleeve 59 about which a collar 60 is rotatably fixed.

Pivoted on the bearing 50, by a pivot bolt 6|, is a cross lever 62. A link 63 pivotally connects one end of this cross lever with the lower end of shaft 56, and. a link 65 likewise pivotally connects the other end of lever 62 with the sleeve The lever 62, as shown in Fig. 5, has downwardly extending actuating rods 6'! and 68 pivotally connected to its opposite ends, and when the causes the collars '58 and 66 to be shifted toward or from each other accordingly.

Attached pivotally to the collars 58 and 60 in positions in alinement with the three wings,

. are sets of toggle links 10, each of which sets fect propulsion and steering has pivoted connection with the inner end of I a link 12 which is connected at its outer end to the corresponding rocker lever 44.

Thus, it will be understood that under'control of the rods 67 and 68, the cross lever 62 may be rocked on its pivot, thereby to simultaneously actuate the three sets of toggle links 10, which, in turn, will actuate to equal extent, the rocker levers 44 of the three Wings. The actuation of lovers 44 will, through the cable connections 45, control the positions of the ailerons 35. The connection of the toggle linkage "it with the shaft 56 is such that there is no interference by rotation of the screws.

Rotation of the air screws results in lifting forces being applied to the craft, and the speed ,of rotation of screws determines the rate of lift or vertical travel. However, if it is desired to cause the craft to move in a forward or backward direction while in horizontal flight, this may be accomplished without change in air screw speed bymanipulation of the ailerons on their hinge shaft mountings either to effect an upward push ordownward push, for the purpose of fore and aft stability and for gliding effect.

To effect horizontal flight and to control speed of travel, I have provided each of the wings of the two air screws with propelling fins orblades which have been shown to best advantage in Figs. 3, 9 and 10.

As shown in Fig. 10, each wing is provided in its under surface, and substantially to its full length, with a downwardly opening channel 75, and contained in each channel is a vertically disposed fin-like member 76 that is attached pivotally at its outerend by a pivot pin or bolt 11 (see Fig. 3) and at its inner end is supported by a sliding connection, as at 18, with the outer end of a rocker lever 19, as best shown in Fig. 9,

. so that the fin may .be adjusted between a position entirely housed within the wing channel,

to a position extending below the wing surface as in Fig. 9. With the understanding that the fins will be extended from the wings or retracted thereinto in timing, it will then be understood that the fins be made to act as a propelling member in connection with the rotation of the wing. The means for control of the fins to efwill. now .be explained.

Each rocker lever 19 is supported intermediate its ends by a pivot bolt 80 forvertical action and at its inner end is pivotally connected by a short link BI with the upper end of a vertically disposed adjusting rod -82 having guided endwise mounting in bearings83 and 84. -Bearings 83 are fixed to the hub portion l6 of the air screw, and bearings 84 are formed in the body portion of gear wheel 20 by which the screw is driven.

At their lower ends, the rods 82 are equipped with spaced rollers 85-85 adapted to travel in contact with the upper and lower surfaces of a circular cam 86 that is mounted for rotary adjustment on the screw mounting spindle l3 below the gear wheel 20.

As seen in Fig. 9, the cam has a gear toothed band 90 cast about its lower end and a beveled gear pinion 9| on a crank shaft 92 rotatable in a bearing 93 which may be rotated by the shaft to effect rotary adjustment of the cam about the spindle.

Each cam has peripheral parts thereof at opposite sides of a diametrical line, designated in Fig. 9 at 86a and 86b, set at different levels, thus, as the screw turns relative to the cam, to cause the rods 82 to be shifted endwise to different positions, and in this way to actuate the corresponding fins 16 into or from their respective wings.

It is to be understood that the propelling action is imparted by the fin only when extended. Therefore, by determining the location of the arc of travel for each screw as rotating about its spindle that the fins are made effective, the direction of travel may be controlled. For example, in consideration of the parts as shown in Fig. 1, and assuming the travel to be in the direction of the arrow at the right-hand end, and the screws I5 and I5 rotating in the direction indicated by arrows B and B, should the propulsion fins of the wings of the forward screw be made effective through the arc defined by the double pointed arrow C, and the fins of the wings of the rearward screw be made effective during the arc of the double pointed arrow C, then the propelling forces of each screw will be balanced with respect to the longitudinal line of travel and effect a direct forward travel. If there should be any deviation from this direct travel, the propulsion arc of one or the other screw could be changed as required to correct the deflection.

For turning the craft, the cams 88 would be adjusted so as to cause the propulsion arcs of the screws to be toward opposite lateral directions, or only one cam might be altered for this directional change, depending upon whether a sharp or long turn is to be made.

Likewise, the cams might be so adjusted or moved as to cause the propelling effect of each screw to be in a direct sidewise direction, or to act as a forward braking force.

In brief, through the proper rotative adjustment and location of the cams 88 on their respective spindles, the fins 16 of the wings of the dual air screws may be made eifective as required for propulsion of the craft in any direction; that is, forward, and lateral for turning, braking and steering control.

I have shown the cams as being individually controlled through the provision of the gears 90 and 9| and crank shafts 92. I have not shown the control devices for the ailerons except to the extent of the rods 61 and 68 in Fig. 3. However, it is here explained that these rods, for each air screw, would extend to a suitable control which might be a stick as used in conventional types of airplanes, for aileron control.

With the aircraft so equipped with dual air screws, rotating in opposite directions. and the wings of each e uipped with the propulsion fins and ailerons, as described, and these operable under the controls shown and described, it is possible to soar directly upward; to travel at high speed under the propelling forces, to move laterally, to turn abruptly or slowly and to have positive directional control at all times.

Having thus described by invention, what I claim as new therein and desire to secure by Letters Patent is:

1. An air screw for helicopter type aircraft comprising a plurality of rigid radial wings, each having an aileron at its outer end, means for controlling the action and position of the ailerons, and each wing having a propulsion fin mounted longitudinally therein and extending substantially the full length thereof and perpendicular to the plane of rotation, adapted to be extended downwardly therefrom during a part of the rotation of the screw and retracted during the remaining part to cause a horizontally directed propelling force to be applied thereby to the craft.

2. In an aircraft of the helicopter type, an airscrew mounted therein to revolve about a vertical axis for lifting the craft, and comprising a plurality of radially extended wings; each wing having a longitudinal slot in its under side and extending substantially to its full length, a fin disposed therein and extended the full length of the slot, means pivotally securing the fin in the slot at its outer end, and a control member in the wing and connected with the fin at its inner end to adjust the fin about its outer end support from a position enclosed within the slot to a position adjusted outwardly therefrom.

3. A structure as recited in claim 2 wherein said wing is revoluble about a vertical hub and wherein a cam ring encircles the hub and a cam follower is mounted to turn with the wing, said cam follower having an operating connection with the said fin control member for the actuation of the latter.

4. A structure as recited in claim 2 wherein said wing is revoluble about a vertical hub and wherein a cam ring encircles the hub and a cam follower is mounted to turn with the wing, said cam follower having an operating connection with the said fin control member for the actuation of the latter said cam ring being' rotatably adjustable about the hub axis to determine the position of the wing relative to the aircraft when the said fin is extended.

ROBERT E. MULIIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,449,129 Pescara Mar. 20, 1923 1,819,075 Darr Aug. 28, 1931 1,836,406 Smith Dec. 15, 1931 1,912,354 Pescara May 30, 1933 1,989,708 Marriage Feb. 5, 1935 2,233,747 Riedl Mar. 4, 1941 2,372,481 Gagas Mar. 27, 1945 2,384,445 Apostolescu Sept. 11, 1945 2,414,435 Bendix Jan. 21, 1947 2,443,393 Landgraf June 15, 1948 2,445,354 Hoppes July 20, 1948 

